Tiotropium bromide is known from European Patent Application EP 418 716 A1 and has the following chemical structure:

Tiotropium bromide is a highly effective anticholinergic with a long-lasting activity which can be used to treat respiratory complaints, particularly chronic obstructive pulmonary disease (COPD) and asthma. The term tiotropium refers to the free ammonium cation.
For treating the abovementioned complaints, it is useful to administer the active substance by inhalation. In addition to the administration of broncholytically active compounds in the form of metered aerosols and inhalable solutions, the use of inhalable powders containing active substance is of particular importance.
With active substances which have a particularly high efficacy, only small amounts of the active substance are needed per single dose to achieve the desired therapeutic effect. In such cases, the active substance has to be diluted with suitable excipients in order to prepare the inhalable powder. Because of the large amount of excipient, the properties of the inhalable powder are critically influenced by the choice of excipient. When choosing the excipient, its particle size is particularly important. As a rule, the finer the excipient, the poorer its flow properties. However, good flow properties are a prerequisite for highly accurate metering when packing and dividing up the individual doses of preparation, e.g., when producing capsules for powder inhalation or when the patient is metering the individual dose before using a multi-dose inhaler. It has also been found that the particle size of the excipient has a considerable influence on the proportion of active substance in the inhalable powder which is delivered for inhalation. The term inhalable proportion of active substance refers to the particles of the inhalable powder which are conveyed deep into the branches of the lungs when inhaled with a breath. The particle size required for this is between 1 μm and 10 μm, preferably less than 5 μm.
Finally, it has been found that the intended therapeutic effect upon the administration of a pharmaceutical composition via inhalation can be decisively influenced by the inhalation device.
Accordingly, the aim of the invention is to provide for a therapeutically efficient method for the administration of inhalable powders containing tiotropium. Another object of the invention is to provide for an inhalation kit comprising a tiotropium containing powder and an inhalation device, the kit being applicable in the method for administration mentioned before.